U.S. patent number 10,508,871 [Application Number 15/314,676] was granted by the patent office on 2019-12-17 for refrigerant distributor, and heat pump device having the refrigerant distributor.
This patent grant is currently assigned to Mitsubishi Electric Corporation. The grantee listed for this patent is Mitsubishi Electric Corporation. Invention is credited to Nobuaki Miyake, Yuudai Morikawa, Akio Murata, Yoshihiko Satake, Hiroshi Yamaguchi.
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United States Patent |
10,508,871 |
Satake , et al. |
December 17, 2019 |
Refrigerant distributor, and heat pump device having the
refrigerant distributor
Abstract
A refrigerant distributor includes an inflow portion made of
aluminum into which refrigerant flows through an inflow pipe, and a
distributing portion made of aluminum that distributes incoming
refrigerant to a plurality of outflow pipes. The distributing
portion includes a main body portion connected to the inflow
portion, and a plurality of outflow portions connected to the
outflow pipes. The outflow portions are protruded from the main
body portion, and are formed integrally with the main body
portion.
Inventors: |
Satake; Yoshihiko (Tokyo,
JP), Miyake; Nobuaki (Tokyo, JP), Morikawa;
Yuudai (Tokyo, JP), Murata; Akio (Tokyo,
JP), Yamaguchi; Hiroshi (Tokyo, JP) |
Applicant: |
Name |
City |
State |
Country |
Type |
Mitsubishi Electric Corporation |
Tokyo |
N/A |
JP |
|
|
Assignee: |
Mitsubishi Electric Corporation
(Tokyo, JP)
|
Family
ID: |
55018684 |
Appl.
No.: |
15/314,676 |
Filed: |
March 30, 2015 |
PCT
Filed: |
March 30, 2015 |
PCT No.: |
PCT/JP2015/059983 |
371(c)(1),(2),(4) Date: |
November 29, 2016 |
PCT
Pub. No.: |
WO2016/002280 |
PCT
Pub. Date: |
January 07, 2016 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20170184351 A1 |
Jun 29, 2017 |
|
Foreign Application Priority Data
|
|
|
|
|
Jul 4, 2014 [WO] |
|
|
PCT/JP2014/067989 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F25B
39/00 (20130101); F25B 39/028 (20130101); F28D
1/0477 (20130101); F28F 9/0275 (20130101); F25B
2339/0444 (20130101) |
Current International
Class: |
F28F
9/02 (20060101); F25B 39/00 (20060101); F25B
39/02 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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54-150541 |
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Nov 1979 |
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JP |
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63-264293 |
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Nov 1988 |
|
JP |
|
63264293 |
|
Nov 1988 |
|
JP |
|
H04-148167 |
|
May 1992 |
|
JP |
|
H08-159615 |
|
Jun 1996 |
|
JP |
|
H08-226729 |
|
Sep 1996 |
|
JP |
|
H11-316066 |
|
Nov 1999 |
|
JP |
|
2004-330266 |
|
Nov 2004 |
|
JP |
|
2005-114214 |
|
Apr 2005 |
|
JP |
|
2005-292035 |
|
Apr 2005 |
|
JP |
|
2006-112606 |
|
Apr 2006 |
|
JP |
|
2012013289 |
|
Jan 2012 |
|
JP |
|
5328724 |
|
Aug 2013 |
|
JP |
|
WO 2013118465 |
|
Aug 2013 |
|
JP |
|
2013-234828 |
|
Nov 2013 |
|
JP |
|
2013-242088 |
|
Dec 2013 |
|
JP |
|
5713509 |
|
May 2015 |
|
JP |
|
2010/119555 |
|
Oct 2010 |
|
WO |
|
Other References
Office Action dated Jun. 6, 2017 issued in corresponding JP
application No. 2016-531145 (and English translation). cited by
applicant .
International Search Report of the International Searching
Authority dated Jun. 2, 2015 for the corresponding international
application No. PCT/JP2015/059983 (and English translation). cited
by applicant .
Office action dated Jul. 24, 2018 issued in corresponding JP patent
application No. 2016-531145 (and English translation attached)
cited by applicant .
Office action dated Mar. 20, 2018 issued in corresponding JP patent
application No. 2016-531145 (and English translation attached).
cited by applicant .
Office action dated Aug. 28, 2018 issued in corresponding CN patent
application No. 201580035160.2 (and English translation attached).
cited by applicant.
|
Primary Examiner: Schneider; Craig M
Assistant Examiner: Hicks; Angelisa L.
Attorney, Agent or Firm: Posz Law Group, PLC
Claims
The invention claimed is:
1. A refrigerant distributor comprising: an inflow portion into
which refrigerant flows from an inflow pipe; and a distributing
portion configured to distribute refrigerant from the inflow
portion to a plurality of outflow pipes, the distributing portion
including: a main body portion connected to the inflow portion, and
a plurality of outflow portions connected to the outflow pipes, the
outflow portions protruding from the main body portion, and being
unitary with and formed integrally with the main body portion, such
that a heat capacity difference between the outflow pipes and the
distributing portion is small longitudinal axes of the plurality of
outflow portions and a longitudinal axis of the main body portion
are substantially parallel.
2. The refrigerant distributor of claim 1, wherein the distributing
portion is formed by press working.
3. The refrigerant distributor of claim 1, wherein the main body
portion is formed by drawing.
4. The refrigerant distributor of claim 1, wherein the main body
portion has a cylindrical space communicating with outflow holes
that open into the outflow portions, and wherein an inner periphery
of the cylindrical space is configured so as to be in contact with
inner peripheries of the outflow holes.
5. The refrigerant distributor of claim 1, wherein the distributing
portion, the inflow portion, the outflow pipes, and the inflow pipe
are made of aluminum, and wherein the outflow portions are brazed
to the outflow pipes, the main body portion is brazed to the inflow
portion, and the inflow portion is brazed to the inflow pipe.
6. The refrigerant distributor of claim 5, wherein an axial length
of the outflow portions is equal to or greater than half of an
axial brazing length of the outflow portions and the outflow
pipes.
7. The refrigerant distributor of claim 1, wherein the outflow
portions have a circular pipe shape, and an outside diameter and a
wall thickness of the outflow portions are same as an outside
diameter and a wall thickness of the outflow pipes.
8. The refrigerant distributor of claim 1, wherein the inflow
portion has a cylindrical portion connected to the inflow pipe, and
a disk portion connected to the main body portion, and the inflow
pipe is disposed on an inner surface side of the cylindrical
portion, wherein the disk portion is disposed on an inner surface
side of the main body portion, and wherein one ends of the outflow
portions are disposed on inner surface sides of expanded portions
with which the outflow pipes are provided.
9. The refrigerant distributor of claim 1, wherein the inflow
portion has a cylindrical portion connected to the inflow pipe, and
a disk portion connected to the main body portion, wherein the
inflow pipe is disposed on an outer surface side of the cylindrical
portion, wherein a cylindrical rib on an inner surface side of
which the main body portion is disposed is formed on an outer
periphery of the disk portion, and wherein expanded portions on
inner surface sides of which the outflow pipes are disposed are
formed at the one ends of the outflow portions.
10. The refrigerant distributor of claim 1, wherein the outflow
portions each have a circular pipe shape, an inside diameter of the
outflow portions is substantially same as an outside diameter of
the outflow pipes, and a wall thickness of the outflow portions is
1 to 2 times a wall thickness of the outflow pipes.
11. The refrigerant distributor of claim 1, wherein in outflow
holes that open into the outflow portions, pipe stopper portions
each having a diameter smaller than an inside diameter of the
outflow holes are formed.
12. The refrigerant distributor of claim 1, wherein at the one ends
of the outflow portions, flare portions that expand to outsides of
the outflow portions are formed.
13. The refrigerant distributor of claim 1, wherein the inflow
portion has a cylindrical portion connected to the inflow pipe, and
an outer peripheral cylindrical portion connected to the main body
portion, and the inflow pipe is disposed on an inner surface side
of the cylindrical portion, wherein the outer peripheral
cylindrical portion is disposed on an inner surface side of the
main body portion, and wherein the one ends of the outflow pipes
are disposed on inside diameter sides of the outflow portions.
14. The refrigerant distributor of claim 1, wherein brazing filler
metal rings containing zinc are each disposed around the
corresponding outflow portions, and, by heating the brazing filler
metal rings, a sacrificial protection layer containing zinc is
formed at least on an upper surface of the main body portion.
15. The refrigerant distributor of claim 14, wherein the brazing
filler metal rings includes two rings, outer peripheral brazing
filler metal rings disposed on outer side of a circumscribed
circles of the plurality of outflow portions, and an inner
peripheral brazing filler metal ring disposed on an inner side of
an inscribed circle of the plurality of outflow portions.
16. The refrigerant distributor of claim 1, wherein a plug or a
bypass pipe is attached to part of the plurality of outflow
portions, and the part of the outflow portions is plugged.
17. The refrigerant distributor of claim 1, wherein the inflow
portion has a throttle portion in which a cross-sectional area of a
refrigerant flow passage is reduced.
18. A heat pump device comprising the refrigerant distributor of
claim 1.
19. The refrigerant distributor of claim 1, wherein the
distributing portion including the main body portion and the
plurality of outflow portions is formed by press working, wherein
the main body portion, which is connected to the inflow portion,
has a cylindrical space communicating with outflow holes that open
into the outflow portions which protrude from the main body
portion, and wherein an inner periphery of the cylindrical space is
configured so as to be in contact with inner peripheries of the
outflow holes.
20. A refrigerant distributor comprising: an inflow portion into
which refrigerant flows from an inflow pipe; and a distributing
portion configured to distribute the refrigerant from the inflow
portion to a plurality of outflow pipes, the distributing portion
including: a main body portion that is connected to the inflow
portion and that is provided with minute protrusions at regular
intervals on a connection surface thereof, and a plurality of
outflow portions that are connected to the outflow pipes and that
are unitary with and integrally formed with, and protrude from, the
main body portion, such that a heat capacity difference between the
outflow pipes and the distributing portion is small longitudinal
axes of the plurality of outflow portions and a longitudinal axis
of the main body portion are substantially parallel.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a U.S. national stage application of
PCT/JP2015/059983 filed on Mar. 30, 2015, which claims priority to
International Patent Application No. PCT/JP2014/067989 filed on
Jul. 4, 2014, the contents of which are incorporated herein by
reference.
TECHNICAL FIELD
The present invention relates to a refrigerant distributor, and a
heat pump device having the refrigerant distributor.
BACKGROUND ART
In a heat exchanger functioning as a condenser or an evaporator of
a refrigeration cycle apparatus such as an air-conditioning
apparatus or a refrigeration apparatus, when a refrigerant flow
passage therein is divided into a plurality of paths, a refrigerant
distributor that distributes refrigerant to each path is necessary
at the entrance of the heat exchanger.
For example, in a multi-type air-conditioning apparatus in which a
plurality of outdoor units or indoor units are connected in
parallel, a refrigerant distributor is necessary to distribute
refrigerant from a main refrigerant flow passage to each unit.
Such a refrigerant distributor is desired to perform distribution
to a plurality of paths more equally and with less unevenness from
the viewpoint of further performance improvement of an
air-conditioning apparatus. In recent years, aluminum has been
increasingly used in air-conditioning parts from the viewpoint of
product weight reduction and improvement in cost-performance ratio
based on material workability.
When heat transfer tubes of a heat exchanger are copper pipes, a
distributing portion of a refrigerant distributor is formed of
copper or brass by shaving processing, and outflow pipes and an
inflow pipe are formed of copper. The outflow pipes are brazed to
the distributing portion, the inflow pipe is brazed to the
distributing portion, and the outflow pipes are brazed to heat
transfer tubes of the heat exchanger.
In a conventional refrigerant distributor 1, the heat capacity of
outflow pipes 2 is small, and the heat capacity of a distributing
portion 3 is large as shown in FIG. 8. Therefore, the heat capacity
difference is large, and, when joining both members by burner
brazing, temperature control is difficult, and brazability is not
stable. To solve this problem of burner brazing, from the viewpoint
of improvement in reproducibility of heat input, a high-frequency
induction heating coil is commonly used as a brazing heating unit
in the production site of a refrigerant distributor (especially
made of copper or brass).
When the heat transfer tubes are made of aluminum, the distributing
portion 3 of the refrigerant distributor 1 is formed of aluminum by
shaving processing, and the distributing portion 3, the outflow
pipes 2, and the inflow pipe 4 are also made of aluminum. The
outflow pipes 2 are brazed to the distributing portion 3, and the
inflow pipe 4 is brazed to the distributing portion 3.
On this occasion, in aluminum brazing, the melting point of brazing
filler metal is about 580 degrees C., whereas the melting point of
base material is about 650 degrees C., and the difference between
the melting point of brazing filler metal and the melting point of
base material, that is, the allowable temperature range is as small
as about 70 degrees C., a fraction of that in copper brazing.
Therefore, when performing joining by burner brazing, the heat
capacity of the distributing portion 3 having a solid cylinder
structure is large, temperature unevenness is likely to occur
between the radially inner and outer parts, the allowable
temperature range is partially exceeded, the base material melts,
on the other hand a region where brazing filler metal is unmelted
is formed, temperature control is difficult, and brazability is
worsened. When a high-frequency induction heating coil is used, the
reproducibility of heat input improves. However, because
high-frequency current flows mainly at the surface of the work due
to skin effect, heating is local, and, in the case of aluminum,
base material is likely to melt.
That is, when joining a distributing portion 3 of an aluminum
refrigerant distributor and outflow pipes 2, there is a problem in
that, because the number of the outflow pipes 2 is large, the
difference in melting point between brazing filler metal and base
metal is small, and the heat capacity difference between the
outflow pipes 2 and the distributing portion 3 is large, it is
difficult to secure highly reliable brazing.
So, hitherto, in particular, the joining of outflow pipes 2 and a
distributing portion 3 different in heat capacity has been
performed by furnace brazing to eliminate cumbersomeness of
temperature control (see, for example, Patent Literature 1).
Because a distributing portion 3 of a refrigerant distributor 1 is
formed by shaving processing, in the case of aluminum, there is
also a problem in that, because machinability is poor and machining
takes time compared to copper or brass, processing cost is
high.
CITATION LIST
Patent Literature
Patent Literature 1: Japanese Patent No. 5328724
SUMMARY OF INVENTION
Technical Problem
As described above, hitherto, the making of an aluminum refrigerant
distributor has been achieved by furnace-brazing members different
in heat capacity as described in Patent Literature 1. However, from
the viewpoint of the size of the furnace, assembling workability,
and the like, not all the members can be furnace-brazed. For
example, an end of an outflow pipe that is too long to place in a
furnace is partially burner-brazed as a separate member. Therefore,
the number of member is large, the number of brazing places is also
large, and the manufacturing process is cumbersome. There is a
problem in that a furnace requires relatively large cost and space,
and is therefore difficult to widely use for products.
There is a problem in that, when all the junctions are
burner-brazed, temperature control is difficult and brazability is
not stable when joining members that differ significantly in heat
capacity, such as a distributing portion and outflow pipes. In
particular, in the case of aluminum, when a distributing portion
having a large heat capacity is heated with a burner or by
high-frequency induction, temperature unevenness exceeding the
allowable temperature is likely to occur, the allowable temperature
range is partially exceeded, the base material melts, on the other
hand a region where brazing filler metal is unmelted is formed, and
temperature control is difficult.
In addition, because a distributing portion of a refrigerant
distributor is formed by shaving processing, in the case of
aluminum, there is also a problem in that, because machinability is
poor and machining takes time compared to copper or brass,
processing cost is high.
The present invention is made to solve the above-described
problems, and it is an object of the present invention to obtain a
refrigerant distributor in which the brazing between a distributing
portion and a plurality of outflow pipes is good, that requires a
small manufacturing man-hour, and that is excellent in
productivity, and a heat pump device having the refrigerant
distributor.
Solution to Problem
A refrigerant distributor according to an embodiment of the present
invention includes an inflow portion into which refrigerant flows
through an inflow pipe, and a distributing portion that distributes
incoming refrigerant to a plurality of outflow pipes. The
distributing portion includes a main body portion connected to the
inflow portion, and a plurality of outflow portions connected to
the outflow pipes. The outflow portions are protruded from the main
body portion, and are formed integrally with the main body
portion.
Advantageous Effects of Invention
According to the refrigerant distributor of the present invention,
since the outflow portions of the distributing portion are
protruded from the main body portion and are formed integrally with
the main body portion, the heat capacity difference between the
outflow pipes and the outflow portions is small, burner heat input
can be given locally to the junctions, and therefore temperature
control of burner heat input is facilitated. Therefore, the
distributing portion and the outflow pipes can be satisfactorily
brazed.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 shows the configuration of a heat exchanger employing a
refrigerant distributor according to Embodiment 1.
FIG. 2 is a vertical sectional view of the refrigerant distributor
1 according to Embodiment 1.
FIG. 3 is a sectional view taken along line A-A of the refrigerant
distributor 1 according to Embodiment 1.
FIG. 4 is a sectional view taken along line A-A of another example
1 of the refrigerant distributor 1 according to Embodiment 1.
FIG. 5 is a sectional view taken along line A-A of another example
2 of the refrigerant distributor 1 according to Embodiment 1.
FIG. 6 is a sectional view taken along line A-A of another example
3 of the refrigerant distributor 1 according to Embodiment 1.
FIG. 7 is a vertical sectional view of the refrigerant distributor
1 according to Embodiment 2.
FIG. 8 is a vertical sectional view of a conventional refrigerant
distributor.
FIG. 9 is a vertical sectional view of the refrigerant distributor
1 according to Embodiment 3.
FIG. 10 is a plan view showing the relative size relationship of a
distributing portion 3 according to Embodiment 3.
FIG. 11 is a vertical sectional view showing the relative size
relationship of the distributing portion 3 according to Embodiment
3.
FIG. 12 is a perspective view showing the state before brazing of
the refrigerant distributor 1 according to Embodiment 3 and outflow
pipes 2.
FIG. 13 is a sectional perspective view showing the state before
brazing of the refrigerant distributor 1 according to Embodiment 3
and outflow pipes 2.
FIG. 14 is a vertical sectional view showing the state before
brazing in which a brazing filler metal ring B17 and a brazing
filler metal ring C18 are disposed on the base portions 3f of the
distributing portion 3 according to Embodiment 4.
FIG. 15 is a perspective view showing the state before brazing in
which a brazing filler metal ring B17 and a brazing filler metal
ring C18 are disposed on the base portions 3f of the distributing
portion 3 according to Embodiment 4.
FIG. 16 is a perspective sectional view showing the state before
brazing in which a brazing filler metal ring B17 and a brazing
filler metal ring C18 are disposed on the base portions 3f of the
distributing portion 3 according to Embodiment 4.
FIG. 17 is a detailed sectional view showing the state before
brazing in which a brazing filler metal ring B17 and a brazing
filler metal ring C18 are disposed on the base portions 3f of the
distributing portion 3 according to Embodiment 4.
FIG. 18 is a perspective view showing the state before the brazing
of a distributing portion 3, outflow pipes 2, and a plug 20 in a
product in which the number of distribution N=7 according to
Embodiment 5.
FIG. 19 is a perspective view showing the state before the brazing
of a distributing portion 3, outflow pipes 2, and a bypass pipe 21
in a product in which the number of distribution N=6 according to
Embodiment 5.
FIG. 20 is a sectional view showing the state before the brazing of
a distributing portion 3, outflow pipes 2, and a bypass pipe 21 in
a product in which the number of distribution N=6 according to
Embodiment 5.
DETAILED DESCRIPTION
Embodiments of the present invention will now be described below
with reference to the drawings. The present invention is not
limited to the embodiments described below. In the following
drawings, the relative size relationship of components may be
different from the actual one.
Embodiment 1
First, the configuration of a fin and tube type heat exchanger 100
employing a refrigerant distributor 1 of Embodiment 1 will be
described.
FIG. 1 shows the configuration of a heat exchanger employing a
refrigerant distributor according to Embodiment 1. A heat pump
device 11 may comprise the refrigerant distributor 1.
For example, when the heat exchanger 100 functions as an
evaporator, the refrigerant distributor 1 according to Embodiment 1
distributes two-phase refrigerant flowing into the fin and tube
type heat exchanger 100 formed by heat transfer tubes 50 and fins
51, and the details will be described later. The two-phase
refrigerant flowing through an inflow pipe 4 into the refrigerant
distributor 1 branches to each outflow portion 3a in a main body
portion 3b of a distributing portion 3, and flows through outflow
pipes 2 into the heat transfer tubes 50 forming the paths of the
heat exchanger 100.
The two-phase refrigerant flowing into the heat transfer tubes 50
of the heat exchanger 100 exchanges heat with air passing through
the heat exchanger 100, through the fins 51 integrated with the
heat transfer tubes 50, and evaporates to become gas refrigerant.
The gas refrigerant converges in a gas header 52, and flows out
toward the suction side of a compressor (not shown).
The heat transfer tubes 50 and the fins 51 are both formed of
aluminum or aluminum alloy. The heat transfer tubes 50 may be
circular pipes, flat pipes, or pipes having any other shape.
Next, the configuration of the refrigerant distributor 1 will be
described.
FIG. 2 is a vertical sectional view of the refrigerant distributor
1 according to Embodiment 1.
FIG. 3 is a sectional view taken along line A-A of the refrigerant
distributor 1 according to Embodiment 1.
The refrigerant distributor 1 of Embodiment 1 is formed by an
inflow portion 5 made of aluminum and a distributing portion 3 made
of aluminum. The distributing portion 3 is formed by press working
integrally with a plurality of outflow portions 3a, and has a
cylindrical main body portion 3b and, for example, four cylindrical
outflow portions 3a. In the upper surface of the main body portion
3b of the distributing portion 3, as shown in FIG. 2, outflow holes
3d communicating with the outflow pipes 2 open. The inflow portion
5 is formed by a circular disk portion 5a and a cylindrical portion
5b disposed coaxially with the central axis of the disk portion
5a.
The outflow pipes 2 are provided with expanded portions 2a in which
the lower ends in FIG. 1 are expanded so as to be fitted on the
outflow portions 3a from the outside, and that have a large bore
compared to base portions 2b. Therefore, when fitting the outflow
pipes 2 onto the outflow portions 3a, the expanded portions 2a are
inserted into the outflow portions 3a, stepped portions between the
base portions 2b and the expanded portions 2a of the outflow pipes
2 are abutted on the upper ends of the outflow portions 3a, and
positioning is thereby performed.
The outside diameter and wall thickness of the base portions 2b of
the outflow pipes 2 are preferably the same as the outside diameter
and wall thickness of the outflow portions 3a of the distributing
portion 3.
When joining the distributing portion 3 and the inflow portion 5,
the outer periphery of the disk portion 5a of the inflow portion 5
is fitted into a circular cutout portion 3c formed in a
circumferential surface at the lower end of the main body portion
3b. When joining the inflow pipe 4 and the inflow portion 5, the
outer peripheral surface of the cylindrical inflow pipe 4 is fitted
into a circular cutout portion 5c formed in the inner peripheral
surface of the lower end of the cylindrical portion 5b of the
inflow portion 5.
After that, the distributing portion 3 and the inflow portion 5 are
joined by burner brazing, then the inflow pipe 4 and the inflow
portion 5 are joined by burner brazing, and the outflow pipes 2 and
the outflow portions 3a are joined by burner brazing.
A burner brazing method is a joining method in which, as with the
Nocolok brazing method, which is furnace brazing, after applying
fluoride flux to a junction and placing brazing filler metal on the
junction, the brazing filler metal is heated with a burner to the
melting point 590 degrees C., and the brazing filler metal is
melted to perform joining. A gas burner uses gas such as city gas,
propane, or mixed gas of acetylene and oxygen.
Burner brazing is performed in the atmosphere, and a junction is
directly heated with a burner, and therefore temperature control is
difficult. In particular, in the case of brazing aluminum members,
because aluminum does not undergo a change in color near the
melting point, and the difference in melting point between brazing
filler metal and base material is small, the brazability is poor.
If brazing is not successful, and joining is incomplete,
refrigerant flowing therethrough leaks to the outside air.
However, since the refrigerant distributor 1 according to
Embodiment 1 is configured such that the outside diameter and wall
thickness of the base portions 2b of the outflow pipes 2 are the
same as the outside diameter and wall thickness of the outflow
portions 3a of the distributing portion 3, the heat capacity
difference between the outflow portions 3a and the outflow pipes 2
in junctions 6 can be reduced, and in addition, burner heat input
can be given locally also to the junctions 6, and therefore
temperature control of burner heat input is facilitated, and the
distributing portion 3 and the outflow pipes 2 can be
satisfactorily brazed.
Since the distributing portion 3 and the inflow portion 5 are
formed by press working, shaving processing is eliminated, working
man-hour can be reduced, and productivity can be improved.
Since the heat capacity of the outflow portions 3a provided in the
upper part of the distributing portion 3 is small, burner brazing
time per junction 6 can be reduced, and productivity can be
improved.
Since the outflow portions 3a are provided in the upper part of the
distributing portion 3 and are integrally formed by press working,
the number of brazing points of the outflow pipes 2, which is two
per flow passage in the conventional refrigerant distributor shown
in FIG. 8, can be reduced to one, and productivity can be
improved.
FIGS. 4 to 6 show modifications of the distributing portion 3 of
the refrigerant distributor 1 according to Embodiment 1.
FIG. 4 is a sectional view taken along line A-A of another example
1 of the refrigerant distributor 1 according to Embodiment 1.
FIG. 5 is a sectional view taken along line A-A of another example
2 of the refrigerant distributor 1 according to Embodiment 1.
FIG. 6 is a sectional view taken along line A-A of another example
3 of the refrigerant distributor 1 according to Embodiment 1.
Although, in FIGS. 4 to 6, examples in which the number of outflow
holes 3d of the distributing portion 3 is two, six, and eight are
shown, the distributing portion 3 may have any number of outflow
holes 3d.
Embodiment 2
A refrigerant distributor 1 according to Embodiment 2 is the same
as the refrigerant distributor according to Embodiment 1 except for
the configuration of junctions between the inflow pipe 4 and the
inflow portion 5, between the distributing portion 3 and the inflow
portion 5, and between the outflow pipes 2 and the outflow portions
3a. So, the difference from the refrigerant distributor 1 according
to Embodiment 1 will be mainly described.
FIG. 7 is a vertical sectional view of the refrigerant distributor
1 according to Embodiment 2.
The outflow portions 3a are provided with expanded portions 3e in
which the upper ends in FIG. 7 are expanded so as to be fitted on
the outflow pipes 2 from the outside, and that have a large bore
compared to the outflow portions 3a. Therefore, when fitting the
outflow pipes 2 into the expanded portions 3e, the outflow pipes 2
are inserted into the expanded portions 3e, the lower ends of the
outflow pipes 2 are abutted on stepped portions between the outflow
portions 3a and the expanded portions 3e, and positioning is
thereby performed.
The outside diameter and wall thickness of the outflow pipes 2 are
preferably the same as the outside diameter and wall thickness of
the outflow portions 3a of the distributing portion 3.
When joining the distributing portion 3 and the inflow portion 5,
the lower end of the main body portion 3b is fitted on the inner
peripheral surface of the cylindrical rib 5d erected on the outer
periphery of the disk portion 5a of the inflow portion 5. When
joining the inflow pipe 4 and the inflow portion 5, the inner
peripheral surface of the cylindrical inflow pipe 4 is fitted into
a cutout portion 5e formed in the outer peripheral surface of the
lower end of the cylindrical portion 5b of the inflow portion
5.
After that, the distributing portion 3 and the inflow portion 5 are
joined by burner brazing, then the inflow pipe 4 and the inflow
portion 5 are joined by burner brazing, and the outflow pipes 2 and
the outflow portions 3a are joined by burner brazing.
In the refrigerant distributor 1 according to Embodiment 2, the
junction 6 between the outflow pipes 2 and the outflow portions 3a,
the junction 7 between the distributing portion 3 and the inflow
portion 5, and the junction 8 between the inflow pipe 4 and the
inflow portion 5 are all joined in such a manner that the lower
member is on the outer side and receives the upper member, and
therefore the outflow pipes 2, the distributing portion 3, the
inflow pipe 4, and the inflow portion 5 can be joined by brazing at
the same time without changing brazing posture. Therefore, the
brazing man-hour can be reduced, and productivity can be
improved.
Since brazing can be performed at the same time without changing
brazing posture, not only burner brazing but also automatic brazing
and furnace brazing can be used, unevenness in heat input due to a
working method can be suppressed, and the brazing temperature
control can be facilitated.
The brazing process of the refrigerant distributor 1 according to
Embodiment 2 in which work is performed at the same time can also
be used in a state in which the refrigerant distributor 1 according
to Embodiment 1 is upside down.
Since, as in Embodiment 1, the outside diameter and wall thickness
of the outflow pipes 2 are the same as the outside diameter and
wall thickness of the outflow portions 3a of the distributing
portion 3, the heat capacity difference between the outflow
portions 3a and the outflow pipes 2 in junctions 6 can be reduced,
and in addition, burner heat input can be given locally also to the
junctions 6, and therefore temperature control of burner heat input
is facilitated, and the distributing portion 3 and the outflow
pipes 2 can be satisfactorily brazed.
Since the distributing portion 3 and the inflow portion 5 are
formed by press working, shaving processing is eliminated, working
man-hour can be reduced, and productivity can be improved.
Since the heat capacity of the outflow portions 3a provided in the
upper part of the distributing portion 3 is small, burner brazing
time per junction 6 can be reduced, and productivity can be
improved.
Since the outflow portions 3a are provided in the upper part of the
distributing portion 3 and are integrally formed by press working,
the number of brazing points of the outflow pipes 2, which is two
per flow passage in the conventional refrigerant distributor shown
in FIG. 8, can be reduced to one, and productivity can be
improved.
Embodiment 3
A refrigerant distributor 1 according to Embodiment 3 is
substantially the same as the refrigerant distributor according to
Embodiment 1 except for the configuration of junctions between the
outflow pipes 2 and the outflow portions 3a. So, the difference
from the refrigerant distributor 1 according to Embodiment 1 will
be mainly described.
FIG. 9 is a vertical sectional view of the refrigerant distributor
1 according to Embodiment 3.
FIG. 10 is a plan view showing the relative size relationship of a
distributing portion 3 according to Embodiment 3.
FIG. 11 is a vertical sectional view showing the relative size
relationship of the distributing portion 3 according to Embodiment
3.
A main body portion 3b of the distributing portion 3 is formed by
cold forging press-like drawing (forging drawing) of a thick plate.
The main body portion 3b is formed by a top plate portion 3g and a
cylindrical body portion 3h having a cylindrical space 3j therein.
A corner portion 16 having a rounded shape for stress relaxation is
provided in the corner part where the lower surface portion 3i of
the top plate portion 3g and the body portion 3h meet.
An inflow portion 5 has an outer peripheral cylindrical portion 5f
provided on the outer peripheral side of a disk portion 5a, and a
cylindrical portion 5b to which an inflow pipe 4 is connected. An
annular cutout portion 10 is formed between the outer peripheral
cylindrical portion 5f and the cylindrical portion 5b. The cutout
portion 10 is formed for suppressing temperature unevenness during
the brazing of the inflow portion 5 to the distributing portion 3,
and for reducing the heat capacity. Several (three or four) center
alignment protrusions for uniformly setting the brazing clearance
between the body portion 3h and the outer peripheral cylindrical
portion 5f are provided on the inner peripheral side of the body
portion 3h at regular intervals as part of the press working (not
shown), so that reliable aluminum brazing is facilitated.
The top plate thickness of the top plate portion 3g required to
secure pressure resisting strength is expressed, using the
relational expression of bending stress of a disk in material
mechanics, as: T.gtoreq.D (0.19P/.sigma.) (Expression 1), where T
[mm] is the thickness of the top plate portion 3g shown in FIG. 10
and FIG. 11, D [mm] is the inside diameter of the body portion 3h,
P [Mpa] is design pressure, and .sigma. [N/mm2] is allowable
tensile stress of material. When the specification of a subject
refrigerant distributor 1 is such that P=4.15 [Mpa] and .sigma.=8
[Mpa] (tensile stress of aluminum thick plate A1070 corrected to a
temperature of 125 degrees C.), T.gtoreq.0.31D.
As for the relative size relationship of the inside diameter D,
Dm.pi..gtoreq.p.times.N>d.times.N (Expression 2), and
D=Dm+(d-2t) (Expression 3), where d [mm] is the outside diameter of
the outflow portions 3a, t [mm] is the wall thickness of the
outflow portions 3a, p [mm] is the distance between pitches of
adjacent outflow portions 3a, N is the number of distribution of
the distributing portion 3, and Dm [mm] is the pitch circle
diameter of the group of outflow portions 3a. From Expression 2 and
Expression 3, there is a relationship:
D.gtoreq.d.times.N/.pi.+(d-2t) (Expression 4).
If values of the outside diameter d=.PHI. 7 mm and the wall
thickness t=1 mm are used as a pipe wall thickness example
complying with High Pressure Gas Safety Act and Refrigeration
Safety Regulations, from Expression 4, D.gtoreq.2.23N+5. If
Expression 4 is substituted in Expression 1, there is a
relationship: T.gtoreq.0.69N+1.55 (Expression 5). When the number
of distribution in this example N=8, substituting this in
Expression 5 yields: T.gtoreq.7 [mm]. To secure required strength
against the design pressure, the thickness T of the top plate
portion 3g is 7 mm (7 times the wall thickness of the outflow
portions 3a) or more. If this is applied to the number of
distribution of applications in general N.gtoreq.3, the thickness T
of the top plate portion 3g is required to be three or more times
larger than the wall thickness of the outflow portions 3a.
The wall thickness of the outflow portions 3a is set so as to be 1
to 2 times the wall thickness of the outflow pipes 2 (for example,
the outflow portions 3a have an outside diameter of .PHI. 7 mm and
a wall thickness of 1 mm, and the outflow pipes 2 have an outside
diameter of .PHI. 5 mm and a wall thickness of 0.7 mm). Base
portions 3f of the outflow portions 3a are formed as part of the
press working in a rounded shape for the purpose of stress
relaxation when excessive external force is applied during the
manufacturing process or the like.
Outflow pipes 2 are fitted on and brazed to the inside diameter
sides of the outflow portions 3a. On this occasion, the lower ends
of the outflow pipes 2 abut on pipe stopper portions 9 disposed in
the outflow holes 3d and are thereby positioned. The pipe stopper
portions 9 are stepped portions that are provided, as part of press
working of the outflow portions 3a, so as to have an inside
diameter slightly smaller than the inside diameter of the outflow
holes 3d. These stepped portions only have to be, for example,
about 0.3 mm in the radial direction. As long as a constraint
condition that these stepped portions have an inside diameter
larger than the inside diameter of the outflow pipes 2 so that
these stepped portions themselves do not cause pressure loss and a
processing constraint condition that each part can be formed by
press working without problems are satisfied, the inside diameter
of the outflow holes 3d may slightly differ between both sides of
the pipe stopper portions 9 (although not shown, only the outflow
portion 3a side parts may have an inside diameter larger than that
of the pipe stopper portions 9).
The depth L from the upper ends of the outflow portions 3a to the
pipe stopper portions 9 in the axial direction of the outflow holes
3d is set, as a fitting depth required for a brazed joint (the
brazing length in the axial direction of the outflow portions 3a
and the outflow pipes 2), such that L.gtoreq.6 mm when the outside
diameter of the outflow pipes 2 is .PHI. 7 mm. The axial length
(height h) of the outflow portions 3a is preferably equal to or
greater than half of the brazing depth L to exert the effect of
Embodiment 3, and is therefore set such that, for example, h=4 mm
in this example.
As can be seen from this example, in the refrigerant distributor 1,
for pressure resistance, the wall thickness ratio T/t of the
thickness T of the top plate portion 3g (=7 mm or more) to the wall
thickness t of the outflow portions 3a (=1 mm) is as high as 7 in
the above example, and 3 or more in applications in general in
which N=3 or more. Therefore, the outflow portions 3a of the
present invention cannot be formed by simple drawing or burring,
which is the same wall thickness level of thin plate processing
like a conventional art (see Japanese Patent No. 2776626 and
Japanese Patent No. 3396770) (according to a conventional art
literature "Design of Progressive Press Die" (Nikkan Kogyo Shimbun,
Ltd.), in burring, because of the constraint of plate thickness
reduction, in the case of aluminum, T/t is specified to be
.ltoreq.1/ 0.29=1.9 at its maximum).
In Embodiment 3, the ratio h/dm of the outflow portion length L (=4
mm or more) to the wall thickness center diameter .PHI. dm (=d-t=6
mm) of N outflow portions 3a is as relatively high as 0.67 or more.
Therefore, in simple drawing, there is such a constraint that
because it is necessary to reduce the disk area of a given region
extending throughout the circumference of the outer edge, it is
difficult to form a plurality of outflow portions. Therefore, in
burring, only the volume of circular rings on the inside diameter
side before processing can be allotted to the volume of the
cylindrical portions of the outflow portions 3a after processing,
there is a limit on the height, and achievement is difficult
(according to the above literature, h/dm.ltoreq.0.25 or less).
So, to form thin and high outflow portions 3a despite such a large
wall thickness difference, it is necessary to press a given region
of a thick plate using a cold forging-like press working to
partially reduce the plate thickness. By securing material of a
volume required for the erection of the outflow portion 3a and
undergoing a plurality of processes using appropriate combination
of punch and die, the material is moved and shaped, and outflow
portions 3a having a desired height are formed.
Since Embodiment 3 uses cold forging-like press working based on
such a volume invariance principle, thin and high outflow portions
3a can be formed from a thick plate. The region where the plate
thickness is reduced is finally directly below the outflow portions
3a. However, in the process of forming the outflow portions 3a, the
present invention is not limited to this, and the necessary region
may be pressed, and material may be moved in and out in a plurality
of processes.
Before joining the distributing portion 3 made of aluminum thus
formed by press working to the outflow pipes 2, in advance, the
distributing portion 3 and the inflow portion 5, and the inflow
pipe 4 and the inflow portion 5 are joined separately or at the
same time by burner brazing or furnace brazing.
FIG. 12 is a perspective view showing the state before brazing of
the refrigerant distributor 1 according to Embodiment 3 and outflow
pipes 2.
FIG. 13 is a sectional perspective view showing the state before
brazing of the refrigerant distributor 1 according to Embodiment 3
and outflow pipes 2.
At the upper ends of the outflow portions 3a, brazing filler metal
rings A13 are disposed in advance, and flare portions 12 that
expand to the outside of the outflow portions 3a are provided as
part of press working of the outflow portions 3a so that brazing
filler metal easily flow into the clearance between themselves and
the outflow pipes 2. The outside diameter of the flare portions 12
is larger than the outside diameter of the outflow portions 3a so
that the brazing filler metal rings A13 are less likely to
overflow.
In this state, a plurality of burners are disposed on the outer
periphery of the main body portion 3b of the distributing portion
3, and are stationary or revolved (the work is rotated or the
burners are revolved), and the outer peripheral side of the main
body portion 3b is heated. Because the main body portion 3b has a
heat capacity corresponding to the thickness of the top plate
portion 3g required for withstanding pressure, in and out
temperature glide in the radial direction and temperature
unevenness in the circumferential direction are likely to occur. On
the other hand, since the outflow portions 3a have a thin wall
thickness and a small heat capacity, and are disposed on the outer
peripheral side of the main body portion 3b, burner heat input
accumulated mainly on the outer peripheral side of the main body
portion 3b spreads throughout the circumference of the outflow
portions 3a by heat transfer, and the outflow portions 3a are
easily temperature-equalized. A phenomenon in which the outflow
portions 3a have less temperature unevenness and are easily
temperature-equalized owing to heat transfer compared to the main
body portion 3b can be confirmed by a heat transfer analysis
simulation and infrared thermography measurement.
When heat is transferred from the thus temperature-equalized and
heated outflow portions 3a to the brazing filler metal rings A13
and the outflow pipes 2, the brazing filler metal rings A13 melt,
and the main body portion 3b and the outflow pipes 2 are brazed. On
this occasion, since the outflow portions 3a have a small heat
capacity and are temperature-equalized compared to the distributing
portion 3, highly reliable brazing free from partial melting of
base material, incomplete melting, short supply of brazing filler
metal, and the like is performed.
The flow of refrigerant in the thus assembled and joined
refrigerant distributor 1 will be described. A throttle portion 14
in which the cross-sectional area of a refrigerant flow passage is
reduced is provided at the upper end of the inflow portion 5 so
that the flow velocity of refrigerant flowing from the inflow pipe
4 can be made appropriate. Refrigerant passing through the throttle
portion 14 collides with a lower surface portion 3i of the top
plate portion 3g. The lower surface portion 3i has a planar shape
unlike a conical surface in a conventional refrigerant distributor.
Therefore, even if refrigerant is an uneven flow such that the
density of flow from the throttle portion 14 is not axially
symmetric, the refrigerant is likely to spread radially outward and
substantially evenly after colliding with the lower surface portion
3i.
The outflow holes 3d are disposed such that their inner peripheries
are substantially in contact with the inner periphery of the
cylindrical space 3j. Therefore, the refrigerant flow 15 radially
spread along the lower surface portion 3i easily flows into the
outflow holes 3d without scattering even when it collides with the
outer wall of the cylindrical space 3j at the termination in the
radial direction, and efficient and substantially even distribution
and outflow of refrigerant are performed.
Embodiment 4
In a refrigerant distributor 1 according to Embodiment 4, the basic
configurations of junctions between the inflow pipe 4 and the
inflow portion 5, the distributing portion 3 and the inflow portion
5, and the outflow pipes 2 and the outflow portions 3a are the same
as those in the refrigerant distributor 1 according to Embodiment
3. So, the difference from the refrigerant distributor 1 according
to Embodiment 3 will be mainly described.
Since aluminum is a corrosion-prone metal, an anticorrosion design
according to the use environment or the like is generally applied
to aluminum pipe parts. Material makers are providing, as an
anticorrosion material for circular pipes themselves, anticorrosion
layer clad pipes that are made by extruding sacrifice anticorrosion
material on the outer surface side at the same time when extruding
pipe material, and zinc spraying pipes that are made by spraying
zinc after extrusion, and, as an anticorrosion material for plate
material, anticorrosion layer clad plates the anticorrosion layers
of which are integrally formed by rolling sacrifice anticorrosion
material at the same time. Of such materials, plate materials
having a relatively small thickness, for which there is a wide
need, are brought to the market, whereas thick materials, for which
there is little need and mass production effect cannot be expected,
are hardly commercialized. Commonly used measures for anticorrosion
of thick parts include retarding the progress of corrosion by
increasing the plate thickness or disposing sacrifice anticorrosion
material such as zinc in the vicinity or on the surface of the
object part.
The distributing portion 3 made of aluminum in Embodiment 4 is
formed from a thick plate by cold forging-like drawing (or
machining) and press working as described above. The main body
portion 3b remains as a thick plate having a plate thickness of 3
mm or more, and therefore keeping the thickness can be a measure
for anticorrosion. However, as for the thin outflow portions 3a, a
measure such as disposing zinc-containing material in the vicinity
is added.
FIG. 14 is a vertical sectional view showing the state before
brazing in which a brazing filler metal ring B17 and a brazing
filler metal ring C18 are disposed on the base portions 3f of the
distributing portion 3 according to Embodiment 4.
FIG. 15 is a perspective view showing the state before brazing in
which a brazing filler metal ring B17 and a brazing filler metal
ring C18 are disposed on the base portions 3f of the distributing
portion 3 according to Embodiment 4.
FIG. 16 is a perspective sectional view showing the state before
brazing in which a brazing filler metal ring B17 and a brazing
filler metal ring C18 are disposed on the base portions 3f of the
distributing portion 3 according to Embodiment 4.
FIG. 17 is a detailed sectional view showing the state before
brazing in which a brazing filler metal ring B17 and a brazing
filler metal ring C18 are disposed on the base portions 3f of the
distributing portion 3 according to Embodiment 4.
As shown in FIGS. 14 to 17, on the top surface of the distributing
portion 3, for the base portions 3f of N outflow portions 3a, there
are disposed an inner peripheral brazing filler metal ring B17
formed so as to have a diameter equal to or smaller than the
diameter of the inscribed circle, and an outer peripheral brazing
filler metal ring C18 formed so as to have a diameter equal to or
larger than the diameter of the circumscribed circle. That is, it
has an outer peripheral brazing filler metal ring C18 disposed on
the outer side of the circumscribed circle of the plurality of
outflow portions 3a, and an inner peripheral brazing filler metal
ring B17 disposed on the inner side of the inscribed circle of the
plurality of outflow portions 3a. The outer peripheral brazing
filler metal ring C18 contains more zinc (Zn) compared to
aluminum-based brazing filler metal for aluminum brazing.
When the distributing portion 3 is heated during the burner brazing
of the outflow pipes 2 and the outflow portions 3a, at the same
time as the ordinary brazing filler metal rings A13 according to
Embodiment 4, the heat input transfers to the inner peripheral
brazing filler metal ring B17 and the outer peripheral brazing
filler metal ring C18 disposed on the base portions 3f, and these
brazing filler metal rings are melted, melted zinc (Zn) is thereby
spread and disposed around the base portions 3f of the outflow
portions 3a and on the upper surface of the top plate portion 3g,
and the sacrifice anticorrosion effect satisfying the corrosion
life can be obtained.
According to Embodiment 4, a measure against corrosion of the
distributing portion 3 consisting of the thick main body portion 3b
and the thin outflow portions 3a in Embodiment 4 can be easily
achieved, without separately requiring a special anticorrosion
treatment process such as zinc spraying or zinc coating, just by
supplying brazing filler metal rings containing zinc at the same
time as ordinary brazing filler metal rings and performing ordinary
brazing heating such as burner.
In Embodiment 4, an example is shown in which, for the base
portions 3f of the outflow portions 3a, an inner peripheral brazing
filler metal ring B17 having a diameter equal to or smaller than
the diameter of the inscribed circle, and an outer peripheral
brazing filler metal ring C18 having a diameter equal to or larger
than the diameter of the circumscribed circle are disposed on the
base portions 3f. A similar effect can be obtained by disposing N
rings of zinc-containing brazing filler metal (not shown) slightly
larger than the outside diameter of the outflow portions 3a on the
base portions 3f. The zinc content and the distance from the
inscribed circle and the circumscribed circle of the base portions
3f of the outflow portions 3a may be determined in advance
according to corrosion environment conditions. Not only brazing
filler metal but also, for example, zinc hoop material itself seems
to be able to be used as the above zinc-containing material.
However, in fact, it is prone to erosion, and attention is
required. Therefore, the applicability thereof can be determined
based on the amount used and brazability.
Embodiment 5
In a refrigerant distributor 1 according to Embodiment 5, the basic
configurations of junctions between the inflow pipe 4 and the
inflow portion 5, the distributing portion 3 and the inflow portion
5, and the outflow pipes 2 and the outflow portions 3a are the same
as those in the refrigerant distributor 1 according to Embodiment
3. So, the difference from the refrigerant distributor 1 according
to Embodiment 3 will be mainly described.
The following method is used to deal with the use of a large number
of distribution N using press working, which is a construction
method having good workability, in Embodiment 5.
FIG. 18 is a perspective view showing the state before the brazing
of a distributing portion 3, outflow pipes 2, and a plug 20 in a
product in which the number of distribution N=7 according to
Embodiment 5.
By performing ordinary burner brazing with one of the outflow
portions 3a of the distributing portion 3 plugged by a plug 20, a
number of distribution (for example, N=7) different from that in
the press working stage (N=8) can be easily dealt with while
utilizing the advantages of the distributing portion 3 such as
press working, workability of brazing, and standardization, and
applying the inexpensive distributing portion 3 together with the
plug 20. To facilitate the aluminum brazing of the plug 20 and the
outflow pipes 2, the heat capacity can be reduced by making the
inflow portion 5 side end face of the plug 20 have a hollow
shape.
FIG. 19 is a perspective view showing the state before the brazing
of a distributing portion 3, outflow pipes 2, and a bypass pipe 21
in a product in which the number of distribution N=6 according to
Embodiment 5.
FIG. 20 is a sectional view showing the state before the brazing of
a distributing portion 3, outflow pipes 2, and a bypass pipe 21 in
a product in which the number of distribution N=6 according to
Embodiment 5.
By performing ordinary burner brazing with two of the outflow
portions 3a of the distributing portion 3 bypassed by a bypass pipe
21, similarly to the above, a number of distribution (for example,
N=6) different from that in the press working stage (N=8) can be
easily dealt with while utilizing the advantages of the
distributing portion 3 such as press working, workability of
brazing, and standardization, and applying the inexpensive
distributing portion 3 together with the bypass pipe 21.
In Embodiment 5, examples are shown in which the distributing
portion 3 of N=8 formed by press working is applied to products of
N=7 and N=6. When the number of distribution of a product is a
divisor of the number of distribution N in the press working stage,
that is, N=2 or N=4 in this example, the rest are plugged by the
above method in such a manner that they are evenly disposed. By
doing so, substantially even distribution can be easily obtained by
that configuration. In the case of other than a divisor, desired
distribution performance design is possible by adjusting and
designing the length of the outflow pipes 2 in advance, according
to the pressure loss in each outflow portion 3a obtained in the
plugged state, to secure even distribution, or by bypassing points,
for example, on a diagonal with the bypass pipe 21, and thereby
minimizing the influence of an uneven flow.
In all of the above embodiments, an example of a burner is shown as
a method for brazing heating. However, the present invention is not
limited to this as long as the features of the distributing portion
3 of the present invention can be utilized. Appropriate heating
methods, such as hot air, a heater (sheathed heater, halogen
heater), high-frequency induction heating, and an electric furnace,
may be combined.
Although five assembly structure examples, Embodiments 1 to 5, have
been shown, of course, the present invention is not limited to this
as long as the features of the distributing portion 3 of the
present invention can be utilized. When the present invention is
applied to a combination structure with outflow pipes 2, an inflow
portion 5, an inflow pipe 4, and a manifold, a similar effect can
be expected.
In the above embodiments, cold forging-like press is used. However,
the present invention is not necessarily limited to this
construction method as long as the thick top plate portion 3g and
the thin outflow portions 3a of the distributing portion 3 are
integrally formed and the features of this example can be utilized.
The cold forging-like press may be combined with machining or
another processing method according to the object product.
Although the refrigerant distributors 1 according to Embodiments 1
to 5 have been described by taking an example in the case where the
heat exchanger 100 functions as an evaporator, the present
invention may be applied to the case where the heat exchanger 100
functions as a condenser. In this case, the refrigerant distributor
1 plays a role in distributing gas refrigerant flowing into the
heat exchanger 100 to each heat transfer tubes 50.
The refrigerant distributors 1 according to Embodiments 1 to 5 are
made of aluminum. Also in the case of a refrigerant distributor
made of brass or copper, which has been heavily used in a
conventional air-conditioning apparatus, the reduction of the heat
capacity of the main body portion 3b, and the reduction of the heat
capacity difference between the outflow portion 3a and the outflow
pipes 2 are desirable in order to perform more reliable brazing.
Therefore, a refrigerant distributor made of brass or copper can be
formed using a press die similar to that for forming a refrigerant
distributor made of aluminum, and a similar effect is exerted.
In recent years, for the purpose of pursuing energy saving,
preventing ozone layer depletion, and preventing global warming,
refrigerants operating at high pressure, such as R410A, R404A, R32,
and CO.sub.2, have tended to be used. Because, compared to the
conventional HCFC refrigerant, the high pressure is high, or the
low pressure is low, improvement in brazing accuracy has a lot of
influence on the prevention of gas leak. According to the present
invention, owing to appropriate heat input to members, stable
brazing can be performed even by a non-skilled worker, and a
refrigerant-leak-free high-quality refrigerant distributor can be
provided.
* * * * *